JERUSALEM
— The newspaper headlines here read like a weather report with a clear forecast: The winds of war are intensifying over the Gaza Strip, the central battlefield of the Israeli-Palestinian conflict.

Since late last week, Israel Defense Forces (IDF) have killed 21 Palestinians; Israeli officials said 18 were "terrorist" militants. Over the past few weeks, there's been a steady resumption of Palestinian Qassam rocket launches into Israel, most causing no major injuries.

This latest round of attacks comes amid widely circulated Israeli reports of a buildup of more sophisticated weapons in Gaza, which could put nearby Israeli communities in the line of fire.

But the return of the violent volley, which crescendoed into outright warfare last June following the capture of an Israeli corporal by Palestinian militants, could be different this time. The lessons of the war between Israel and Hizbullah this summer have led the Israeli establishment to some new conclusions: Waiting while a neighbor arms itself is out; preemptive attacks may be the new norm.

"Israel cannot afford to let Gaza turn into a southern Lebanon," says Gerald Steinberg, a political scientist at Bar Ilan University, near Tel Aviv. "The link is that the longer Israel waits, the more likely that they'll have the same abilities for longer-range and better weapons in Gaza."

For Israel's strategic-minded right, the major error before the war in Lebanon was allowing Hizbullah to build up a large arsenal of short- and medium-range weapons.

Now Israel is concerned that Hamas is trying to emulate the relative successes Hizbullah achieved in the recent war, in which the Iranian-backed militants inflicted a high number of casualties on the Israeli army. The head of the IDF's intelligence research department told the Israeli cabinet Sunday that Hamas is smuggling advanced weaponry into Gaza, including antiaircraft and antitank missiles.

The weapons, warned Brig.-Gen. Yossi Baidatz, whose comments were provided to reporters after the meeting, might make it more difficult for the IDF to launch future ground operations in Gaza. The deputy head of Shin Bet, Israel's internal security agency, also told the cabinet that outside weapons experts had been smuggled into Gaza in recent days.

"This is predictable: Israel's basically run out of alternatives," says Professor Steinberg, who directs Bar Ilan's Interdisciplinary Program on Conflict Management and Negotiation. "It's been a year since disengagement. The rocket attacks continue and the range of the missiles grows. There's no effort to enforce the arrangements that were agreed on at time of disengagement," he charges, such as Egypt patrolling its border with Gaza to prevent smuggling, and the use of European Union monitors.

"The PA is in total disarray, and there's no attempt to prevent Gaza from being used as a launchpad. All of those pieces together lead to a need to pay whatever price is necessary," he says, "to keep it not just from becoming Lebanon, but Somalia."

Israeli-Palestinian fighting in Gaza has undergone gradual changes since Israel exited the coastal territory a year ago this September after 38 years of occupation. Unlike the long military campaigns of the past, Israeli forces now tend to go into Gaza for three-day missions and then get out.

There, in comparison to hilly Lebanon, Israel continues to have the upper hand. Gaza is flat and sandy, making it more difficult for militants to ambush Israeli soldiers and to hide rocket launchers in trees or craggy slopes. But Palestinian digging of underground tunnels – one of which was used by militants to kill two Israeli soldiers on June 25 and capture Cpl. Gilad Shalit – frustrates Israeli attempts to preempt attacks or weapons smuggling.

Ziad Abu Amar, a leading Palestinian legislator in Gaza, views Israel's charge of Palestinian smuggling as hypocritical, given the reasonable assumption that Israel is also beefing up its weapons capabilities in the wake of the summer of war in Gaza, in northern Israel, and in Lebanon.

"Smuggling will happen. We shouldn't be surprised that Hamas is trying to strengthen itself and acquire weapons," says Dr. Abu Amar, who wrote an academic book on Hamas and maintains good ties with the movement, but has declared himself an independent.

"The Israelis claim that new types of weapons and larger amounts are being smuggled, but no one can ascertain what they are. What is the amount? What kind are they talking about? Under the circumstances of occupation and continuing fighting, the Israelis try to upgrade their military arsenal – this is part of the conflict – and so those inside will also try to strengthen the capabilities. The Israelis can't tell the Palestinians, 'Don't fight and acquire weapons,' while they are fighting and acquiring weapons."

The hope that Palestinians hold for more stable days ahead has rested on the concept of a unity government between Hamas and Fatah, allowing the latter – which reached the historic Oslo Peace Accords with Israel in the mid-1990s – to direct negotiations. But that idea, supported by Fatah's Mahmoud Abbas, the Palestinian president, has yet to come to fruition. Abu Amar, a key player in trying to bridge the Palestinian political chasm, says he is not sure it will happen. But he is sure that if it doesn't, violence will fill the void.

"We got entangled in another circle of attacks and counterattacks, rockets and retribution. This is what happens when there is no political horizon to speak of," he says.

"When we were talking about a national unity government that might help end the siege," he says, referring to the multinational freeze on financial aid to the Hamas-led government, "we hoped that might help in a positive direction. If it is blocked, the natural conclusion is to turn to another course of action. Which leaves it open to all possibilities."

Including, says an influential Israeli commentator, the start of a third intifada. He wrote in Monday's Haaretz newspaper that the "unofficial truce [or calm] between Israel and Hamas is evaporating, and the violent hostility between them has become open and clear." The two are on a collision course, he says, and when the crash comes, "it is not going to come as a surprise."